Water-resistant laminated paper and method of manufacture



Patented 14, 1940 v I UNITED STATESPATENT OFFlCE WATER-RESISTANT LAMINATED PAPER AND METHOD OF MANUFACTURE Louis C. Fleck, Appleton, Wis., assignor to Paper Mlatents Company, Neenah, Wis., a corporation of Wisconsin No Drawing. Application June 29, 1936,

Serial No. 87,952 I I 6 Claims. (Cl. 154-50) v The present invention relates to laminated resistant protein adhesive; treating one side of paper and the method of preparing the same. a second sheet of paper with a starch-like adrelief of the embossing is flattened out and the More particularly, the present invention relates hesive containing an agent adapted to render the to paper sheets bonded together with a waterprotein adhesive water-resistant, and pressing resistant binding composition. The laminated the treated sides of the sheets together.

paper prepared in accordance with the present The following example employing twelve ounce invention has been found particularly adapted wall paper will serve to illustrate my invention;

for use in the manufacturing of embossed wall The bonding composition or glue which is used paper. i to bind the paper together is of course made up when regular em ssed wall paper is hung on in separate parts, one part of the glue being aplo the wall by the paper hanger, practically all of plied to the first or bottom sheet and the other the relief present and produced by the embosspart to the second or top sheet just prior to the ing operation will be found to have flattened out pressing of the two sheets together. The first as soon as the paper has dried. This unsatisfacpart of the glue. which may be applied to the first tory result is caused primarily by the fact that or bottom sheet; may be made up of a formula 1 in the ordinary process of paper. hanging the as follows. back of the paper is first covered with a starch Parts paste which is allowed to soak into the paper for Soya bean flour 450 several minutes before applying the paper in the water 1750 wall. During this period in which the paste is Borax dissolved in 1000 parts 01 waters 45 Soaking into the paper, the paper becomes very Phenol -s 22.5

soft and pliable so that, when hung on the wall and rolled or brushed down tight; most of the the adhesive the bean flour is first mixed with enoughwater to form a thick paste and then cut with an alkali suchas borax dissolved in water at about 50 C. according to the usual practice in wall paper mills. The rest of the water and phenol are then added and this part of the glue is ready for use.

embossing effect largely lost.

I have. found that a more permanent embossing effect can be maintained after the paper is hung on the wall if the paper employed. instead of being the ordinary single ply, is made up of a laminated paper consisting of two sheets posted or bonded together with a water-proof film or lied to the second or top sheet is made by glue. The laminated papers heretofore available app have not, however, been found entirely satisfaccooking one part of starch'nke adhesive such mun For example paper bonded with watch astapioca nou r mixed with 19.5 parts of water proof adhesives including latex, cellulose ethers to about 7540' according to the general met-h- 86 and esters, asphalt combinations, and the souse! in wan paper To this called water-proof animal glues. were objectionadded slowly with surfing about 18 parts of able due either to high cost, change in color, or mercm formalin an aqueous solution of v h formaldimculty of appucnone formaldehyde. After 00011118 the stare It is an object of my invention to prepare a dehyde adhesive n o laminated paper employing a water-proof bondin place of born and bean ing composition that does not change in color. other Inns and other amm'soluble potential! It is also an object of my invention to prepare water'resistnt 9 such 3min may a laminated paper employing awatebpmot bomb used. Although the presence of the phenol is The second part of the glue which may be ing composition that is not diflicult of applica- Pneml 4' n stances that react with formaldehyde have been 7 It is a further object of my invention to promum! advflntaleous the? add the duee a laminated paper employing a low cost resistance of the bonded l -l In Place he water-proof bonding composition that is'particu- 9 flour- 80%! as a carrier for the larly suitable for use in making embossed wall n ub i s agent. other s -li adhcd q paper, may be used. The formaldehyde insolnlllillnl I have discovered that aim-improved laminated agent may be partially or totally replaced paper having the desired characteristics may be ,fl fl S l Such 85 u a um um Ill made by treating one side of a sheet of paper phate) and' aluminum formats. 4 The protein adwith an alkaline solution of a potentially waterhesive contain rosinates which will inu 7 carried by thestarch.

solubilise when combined with aluminum salts The starch adhesive may also serve. as a carrier for ilexibilizing agents such as glycerol. a

In the operation of applying the respective adheslves to the top and bottom sheets and making a laminated sheet from the-same, the two rolls of paper consisting of the top and the bottom sheets respectively, are mounted on separate unwinding stands; The paper from each unwinding stand then passes over amachine in which eachsheet of paper receives a coating of its respective adhesive. This machine may be a reverse roll coater, a blotch roller, or a brush coater. It is understood that there is a separate treating machine for each sheet, the proteinadhesive being applied, for example, to one side of the bottom sheet and the starchadhesive being applied to 'oneside of the top sheet. From the machines the respective-sheets pass over a doctor bar or scraper knife which scrapes oif all the .excess adhesive which mightbe piled upon the paper leaving onlya very thin film of adhesive on the surface and some adhesive which has already penetrated into the sheet. After passing over the scraper knives, the two sheets then are run together so that the treated sides are next to each other and in this position the two sheets travel to rollers and are pressed together in the usual manner. If the paper is to be embossed, it travels directly to the embosser, which presses the sheets firmly together at the same time that the embossing is done. The sequence of operation described above is' continuous, the whole operation of applying theadhesive, scraping off the excess, and pressing the sheets together, taking place in a period of a few seconds. The embossing of the somewhat soft, freshly treated paper before the adhesive layer has dried out and completely set to a water-resistant layer, is

the preferred procedure when the paper is to be embossed.

The laminated paper prepared by my process is water-resistant and when embossed retains its relief even when subjected to the most severe of paper hanging treatments. Although the embossing effect is not brushed or flattened out by the paper hanger when soaked with starch paste and hung on the wall, the paper nevertheless becomes pliable and workable for hanging. The

laminated sheets bonded with my low cost bonding composition, which is simple in application,

are not subject to color change and are durable when exposed or stored in warm, damp places under conditions which tend to promote growth of mold and other micro organism Although I have stressed the use of my laminated paper for use in makingembossed wall paper, it will be understood that my paper may be used for wrapping' paper boxes and for all other like uses, and particularly where water- .resistant, durable paper not subjected to color change is desired. It will also be understood that while I have illustrated my invention showing the use as embossed amps.

use of specific compositions, my invention is not I limitedthereto, as all modifications coming within the true spiritand scope'of my invention are intended to be covered by the claims appended hereto.

I claim:

- 1. A method of particularly adapted for use in the manufacture of embossed wallpaper comprising treating one side of a sheet of paper with an alkalinesolution of a potentially water-resistant casein adhesive,-

said laminated paper while treated sides of said sheets I A method of preparing laminated paper.

comprising treating one side of a sheet of paper with an alkaline solution of a potentially waterresistant casein adhesive, treating one side of a second sheet of paper with a water-resistant, and simul-.

preparing starch adhesive containing formaldehyde, and pressingthe freshly 7 treated sides of said sheets together.

4.- A method of comprising treating one side of a sheet of paper with an alkaline solution of a potentially water resistant casein adhesive, treating one side of preparing laminated paper a second sheet of paper with a starch adhesive containing salts of aluminum selected from the group consisting of aluminum sulphate and aluminum formate, and pressing the freshly freshly treated sides of'said sheets together.

,. 5. Laminated paper particularly adapted for wall paper comprising two sheets of paper cemented together with a casein adhesive and a starch adhesive containing acasein insolubilizingagentselected from the group comprising formaldehyde and soluble aluminum salts selected from the group consisting of aluminum sulphate and aluminum formats.

6. A method of preparing laminated paper comprising treating one side of the sheet of paper with a potentially water-resistant casein adhesive containing a small amount of phenol, treating one side of a second sheet of paper with a starch adhesive containing formaldehyde, and I pressing the treated sides'of said sheets together. suflicient formaldehyde being present to insolubilize theca sein adhesive and react with the phenol being effective to phenol, the amount of provide a substantial increase in water resistance ofsaid laminated paper.

LOUISQ. FLECK. 

